diff --git a/src/GF/RGF2_ppBSE_static_kernel_C.f90 b/src/GF/RGF2_ppBSE_static_kernel_C.f90
index 340e55a..cf133ae 100644
--- a/src/GF/RGF2_ppBSE_static_kernel_C.f90
+++ b/src/GF/RGF2_ppBSE_static_kernel_C.f90
@@ -26,9 +26,6 @@ subroutine RGF2_ppBSE_static_kernel_C(ispin,eta,nBas,nC,nO,nV,nR,nVV,lambda,ERI,
   integer                       :: m
   integer                       :: a,b,c,d,e
   integer                       :: a0,aa,ab,cd
-
-  double precision              :: eta2
-  double precision, allocatable :: Om_tmp(:,:)
   
 ! Output variables
 
@@ -37,92 +34,32 @@ subroutine RGF2_ppBSE_static_kernel_C(ispin,eta,nBas,nC,nO,nV,nR,nVV,lambda,ERI,
 ! Initialization
 
   KC_sta(:,:) = 0d0
-! eta2 = eta * eta
-
-! allocate(Om_tmp(nBas,nBas))
-! Om_tmp(:,:) = 0d0
-
-! ! Compute the energy differences and denominator once and store them in a temporary array
-! !$OMP PARALLEL DEFAULT(NONE) PRIVATE(m,e,dem) SHARED(nC,nO,nBas,nR, eta2, eGF, Om_tmp)
-! !$OMP DO
-! do m=nC+1,nO
-!    do e=nO+1,nBas-nR
-!       dem = eGF(m) - eGF(e)
-!       Om_tmp(m,e) = dem / (dem*dem + eta2)
-!    enddo
-! enddo
-! !$OMP END DO
-! !$OMP END PARALLEL
   
 ! Second-order correlation kernel for the block C of the singlet manifold
 
-!  --- --- ---
-!    OpenMP implementation
-!  --- --- ---
+! --- --- ---
+! OpenMP implementation
+! --- --- ---
 
-! if(ispin == 1) then
+if(ispin == 1) then
 
-!   a0 = nBas - nR - nO
-!   !$OMP PARALLEL DEFAULT(NONE)                              &
-!   !$OMP          PRIVATE(a, b, aa, ab, c, d, cd, m, e, num) &
-!   !$OMP          SHARED(nO, nBas, nR, nC, a0, ERI, Om_tmp, KC_sta, lambda)
-!   !$OMP DO
-!   do a=nO+1,nBas-nR
-!     aa = a0 * (a - nO - 1) - (a - nO - 1) * (a - nO) / 2 - nO
-!     do b=a,nBas-nR
-!       ab = aa + b
+  a0 = nBas - nR - nO
+  !$OMP PARALLEL DEFAULT(NONE)                              &
+  !$OMP          PRIVATE(a, b, aa, ab, c, d, cd, m, e, num, dem) &
+  !$OMP          SHARED(nO, nBas, nR, nC, a0, ERI, KC_sta, lambda, eGF, eta)
+  !$OMP DO
+  do a=nO+1,nBas-nR
+    aa = a0 * (a - nO - 1) - (a - nO - 1) * (a - nO) / 2 - nO
+    do b=a,nBas-nR
+      ab = aa + b
 
-!       cd = 0
-!       do c=nO+1,nBas-nR
-!         do d=c,nBas-nR
-!           cd = cd + 1
-! 
-!           do m=nC+1,nO
-!             do e=nO+1,nBas-nR
-!    
-!               num = 2d0*ERI(a,m,c,e)*ERI(b,e,d,m) -     ERI(a,m,c,e)*ERI(b,e,m,d) & 
-!                   -     ERI(a,m,e,c)*ERI(b,e,d,m) -     ERI(a,m,e,c)*ERI(b,e,m,d)
+      cd = 0
+      do c=nO+1,nBas-nR
+        do d=c,nBas-nR
+          cd = cd + 1
 
-!               KC_sta(ab,cd) = KC_sta(ab,cd) + num * Om_tmp(m,e)
-!           
-!               num = 2d0*ERI(b,m,c,e)*ERI(a,e,d,m) -     ERI(b,m,c,e)*ERI(a,e,m,d) & 
-!                   -     ERI(b,m,e,c)*ERI(a,e,d,m) -     ERI(b,m,e,c)*ERI(a,e,m,d)
-
-!               KC_sta(ab,cd) = KC_sta(ab,cd) + num * Om_tmp(m,e)
-!           
-!             end do
-!           end do
-
-!           KC_sta(ab,cd) = 2d0*lambda*KC_sta(ab,cd)/sqrt((1d0 + Kronecker_delta(a,b))*(1d0 + Kronecker_delta(c,d)))
-!           
-!          end do
-!        end do
-
-!     end do
-!   end do
-!   !$OMP END DO
-!   !$OMP END PARALLEL
-
-! end if
-
-!  --- --- ---
-!  Naive implementation
-!  --- --- ---
-
-  if(ispin == 1) then
- 
-    ab = 0
-    do a=nO+1,nBas-nR
-      do b=a,nBas-nR
-        ab = ab + 1
- 
-        cd = 0
-        do c=nO+1,nBas-nR
-          do d=c,nBas-nR
-            cd = cd + 1
- 
-            do m=nC+1,nO
-              do e=nO+1,nBas-nR
+          do m=nC+1,nO
+            do e=nO+1,nBas-nR
    
                 dem = eGF(m) - eGF(e)
                 num = 2d0*ERI(a,m,c,e)*ERI(e,b,m,d) - ERI(a,m,c,e)*ERI(e,b,d,m)  &
@@ -145,18 +82,73 @@ subroutine RGF2_ppBSE_static_kernel_C(ispin,eta,nBas,nC,nO,nV,nR,nVV,lambda,ERI,
                                                                                  
                 KC_sta(ab,cd) = KC_sta(ab,cd) + num*dem/(dem**2 + eta**2) 
           
-              end do
-           end do
- 
-           KC_sta(ab,cd) = lambda*KC_sta(ab,cd)/sqrt((1d0 + Kronecker_delta(a,b))*(1d0 + Kronecker_delta(c,d)))
-          
+            end do
           end do
-        end do
- 
-      end do
+
+          KC_sta(ab,cd) = lambda*KC_sta(ab,cd)/sqrt((1d0 + Kronecker_delta(a,b))*(1d0 + Kronecker_delta(c,d)))
+          
+         end do
+       end do
+
     end do
- 
-  end if
+  end do
+  !$OMP END DO
+  !$OMP END PARALLEL
+
+end if
+
+!  --- --- ---
+!  Naive implementation
+!  --- --- ---
+
+!   if(ispin == 1) then
+   
+!     ab = 0
+!     do a=nO+1,nBas-nR
+!       do b=a,nBas-nR
+!         ab = ab + 1
+   
+!         cd = 0
+!         do c=nO+1,nBas-nR
+!           do d=c,nBas-nR
+!             cd = cd + 1
+   
+!             do m=nC+1,nO
+!               do e=nO+1,nBas-nR
+   
+!                 dem = eGF(m) - eGF(e)
+!                 num = 2d0*ERI(a,m,c,e)*ERI(e,b,m,d) - ERI(a,m,c,e)*ERI(e,b,d,m)  &
+!                      -    ERI(a,m,e,c)*ERI(e,b,m,d) - ERI(a,m,e,c)*ERI(e,b,d,m)
+                                                                                 
+!                 KC_sta(ab,cd) = KC_sta(ab,cd) + num*dem/(dem**2 + eta**2)
+   
+!                 num = 2d0*ERI(a,e,c,m)*ERI(m,b,e,d) - ERI(a,e,c,m)*ERI(m,b,d,e)  &
+!                      -    ERI(a,e,m,c)*ERI(m,b,e,d) - ERI(a,e,m,c)*ERI(m,b,d,e)
+                                                                                 
+!                 KC_sta(ab,cd) = KC_sta(ab,cd) + num*dem/(dem**2 + eta**2) 
+                                                                                 
+!                 num = 2d0*ERI(b,m,c,e)*ERI(e,a,m,d) - ERI(b,m,c,e)*ERI(e,a,d,m)  &
+!                      -    ERI(b,m,e,c)*ERI(e,a,m,d) - ERI(b,m,e,c)*ERI(e,a,d,m)
+                                                                                 
+!                 KC_sta(ab,cd) = KC_sta(ab,cd) + num*dem/(dem**2 + eta**2)
+   
+!                 num = 2d0*ERI(b,e,c,m)*ERI(m,a,e,d) - ERI(b,e,c,m)*ERI(m,a,d,e)  &
+!                      -    ERI(b,e,m,c)*ERI(m,a,e,d) - ERI(b,e,m,c)*ERI(m,a,d,e)
+                                                                                 
+!                 KC_sta(ab,cd) = KC_sta(ab,cd) + num*dem/(dem**2 + eta**2) 
+          
+!               end do
+!            end do
+   
+!            KC_sta(ab,cd) = lambda*KC_sta(ab,cd)/sqrt((1d0 + Kronecker_delta(a,b))*(1d0 + Kronecker_delta(c,d)))
+          
+!           end do
+!         end do
+   
+!       end do
+!     end do
+   
+!   end if
 
 ! Second-order correlation kernel for the block C of the triplet manifold
 
@@ -164,68 +156,26 @@ subroutine RGF2_ppBSE_static_kernel_C(ispin,eta,nBas,nC,nO,nV,nR,nVV,lambda,ERI,
 !  OpenMP implementation
 !  --- --- ---
   
-! if(ispin == 2) then
+if(ispin == 2) then
 
-!   a0 = nBas - nR - nO - 1
-!   !$OMP PARALLEL DEFAULT(NONE)                              &
-!   !$OMP          PRIVATE(a, b, aa, ab, c, d, cd, m, e, num) &
-!   !$OMP          SHARED(nO, nBas, nR, nC, a0, ERI, Om_tmp, KC_sta)
-!   !$OMP DO
-!   do a = nO+1, nBas-nR
-!     aa = a0 * (a - nO - 1) - (a - nO - 1) * (a - nO) / 2 - nO - 1
-!     do b = a+1, nBas-nR
-!       ab = aa + b
+  a0 = nBas - nR - nO - 1
+  !$OMP PARALLEL DEFAULT(NONE)                              &
+  !$OMP          PRIVATE(a, b, aa, ab, c, d, cd, m, e, num, dem) &
+  !$OMP          SHARED(nO, nBas, nR, nC, a0, ERI, KC_sta, eGF, eta)
+  !$OMP DO
+  do a = nO+1, nBas-nR
+    aa = a0 * (a - nO - 1) - (a - nO - 1) * (a - nO) / 2 - nO - 1
+    do b = a+1, nBas-nR
+      ab = aa + b
 
-!       cd = 0
-!       do c=nO+1,nBas-nR
-!         do d=c+1,nBas-nR
-!           cd = cd + 1
-! 
-!           do m=nC+1,nO
-!             do e=nO+1,nBas-nR
-!    
-!               num = 2d0*ERI(a,m,c,e)*ERI(b,e,d,m) -     ERI(a,m,c,e)*ERI(b,e,m,d) &
-!                   -     ERI(a,m,e,c)*ERI(b,e,d,m) +     ERI(a,m,e,c)*ERI(b,e,m,d)
+      cd = 0
+      do c=nO+1,nBas-nR
+        do d=c+1,nBas-nR
+          cd = cd + 1
 
-!               KC_sta(ab,cd) = KC_sta(ab,cd) + 2d0 * num * Om_tmp(m,e)
-!           
-!               num = 2d0*ERI(b,m,c,e)*ERI(a,e,d,m) -     ERI(b,m,c,e)*ERI(a,e,m,d) &
-!                   -     ERI(b,m,e,c)*ERI(a,e,d,m) +     ERI(b,m,e,c)*ERI(a,e,m,d)
-
-!               KC_sta(ab,cd) = KC_sta(ab,cd) - 2d0 * num * Om_tmp(m,e)
-!           
-!             end do
-!           end do
-
-!         end do
-!       end do
-
-!     end do
-!   end do
-!   !$OMP END DO
-!   !$OMP END PARALLEL
-
-! end if
-
-!  --- --- ---
-!  Naive implementation
-!  --- --- ---
-
- if(ispin == 2) then
-
-   ab = 0
-   do a=nO+1,nBas-nR
-     do b=a+1,nBas-nR
-       ab = ab + 1
-
-       cd = 0
-       do c=nO+1,nBas-nR
-         do d=c+1,nBas-nR
-           cd = cd + 1
-
-           do m=nC+1,nO
-             do e=nO+1,nBas-nR
-  
+          do m=nC+1,nO
+            do e=nO+1,nBas-nR
+   
                 dem = eGF(m) - eGF(e)
                 num = 2d0*ERI(a,m,c,e)*ERI(e,b,m,d) - ERI(a,m,c,e)*ERI(e,b,d,m)  &
                      -    ERI(a,m,e,c)*ERI(e,b,m,d) + ERI(a,m,e,c)*ERI(e,b,d,m)
@@ -246,18 +196,71 @@ subroutine RGF2_ppBSE_static_kernel_C(ispin,eta,nBas,nC,nO,nV,nR,nVV,lambda,ERI,
                      -    ERI(b,e,m,c)*ERI(m,a,e,d) + ERI(b,e,m,c)*ERI(m,a,d,e)
                                                                                  
                 KC_sta(ab,cd) = KC_sta(ab,cd) - num*dem/(dem**2 + eta**2) 
-         
-             end do
-           end do
+          
+            end do
+          end do
 
-         end do
-       end do
+        end do
+      end do
 
-     end do
-   end do
+    end do
+  end do
+  !$OMP END DO
+  !$OMP END PARALLEL
+
+end if
+
+!  --- --- ---
+!  Naive implementation
+!  --- --- ---
+
+! if(ispin == 2) then
+
+!    ab = 0
+!    do a=nO+1,nBas-nR
+!      do b=a+1,nBas-nR
+!        ab = ab + 1
+  
+!        cd = 0
+!        do c=nO+1,nBas-nR
+!          do d=c+1,nBas-nR
+!            cd = cd + 1
+  
+!            do m=nC+1,nO
+!              do e=nO+1,nBas-nR
+  
+!                 dem = eGF(m) - eGF(e)
+!                 num = 2d0*ERI(a,m,c,e)*ERI(e,b,m,d) - ERI(a,m,c,e)*ERI(e,b,d,m)  &
+!                      -    ERI(a,m,e,c)*ERI(e,b,m,d) + ERI(a,m,e,c)*ERI(e,b,d,m)
+                                                                                 
+!                 KC_sta(ab,cd) = KC_sta(ab,cd) + num*dem/(dem**2 + eta**2)
+  
+!                 num = 2d0*ERI(a,e,c,m)*ERI(m,b,e,d) - ERI(a,e,c,m)*ERI(m,b,d,e)  &
+!                      -    ERI(a,e,m,c)*ERI(m,b,e,d) + ERI(a,e,m,c)*ERI(m,b,d,e)
+                                                                                 
+!                 KC_sta(ab,cd) = KC_sta(ab,cd) + num*dem/(dem**2 + eta**2) 
+                                                                                 
+!                 num = 2d0*ERI(b,m,c,e)*ERI(e,a,m,d) - ERI(b,m,c,e)*ERI(e,a,d,m)  &
+!                      -    ERI(b,m,e,c)*ERI(e,a,m,d) + ERI(b,m,e,c)*ERI(e,a,d,m)
+                                                                                 
+!                 KC_sta(ab,cd) = KC_sta(ab,cd) - num*dem/(dem**2 + eta**2)
+  
+!                 num = 2d0*ERI(b,e,c,m)*ERI(m,a,e,d) - ERI(b,e,c,m)*ERI(m,a,d,e)  &
+!                      -    ERI(b,e,m,c)*ERI(m,a,e,d) + ERI(b,e,m,c)*ERI(m,a,d,e)
+                                                                                 
+!                 KC_sta(ab,cd) = KC_sta(ab,cd) - num*dem/(dem**2 + eta**2) 
+         
+!              end do
+!            end do
+  
+!          end do
+!        end do
+  
+!      end do
+!    end do
+  
+!   end if
   
-  end if
-
   if(ispin == 4) then
  
     ab = 0